Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 675

April 30, 201137 counties in Arkansas; McCurtain County, Oklahoma; 5 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2011, 11:39 PM CDT for 37 counties in Arkansas; McCurtain County, Oklahoma; 5 counties in Texas. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
Apr 30, 2011, 11:39 PM CDT (04:39 UTC)
Expired
May 1, 2011, 12:45 AM CDT
In force
66 min
Issued by
the Storm Prediction Center
All 43 counties

Arkansas County, AR, Clark County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Cross County, AR, Faulkner County, AR, Garland County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Independence County, AR, Jackson County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Little River County, AR, Lonoke County, AR, Miller County, AR, Monroe County, AR, Montgomery County, AR, Nevada County, AR, Perry County, AR, Phillips County, AR, Pike County, AR, Poinsett County, AR, Polk County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Sevier County, AR, St. Francis County, AR, White County, AR, Woodruff County, AR, Yell County, AR, McCurtain County, OK, Bowie County, TX, Cass County, TX, Morris County, TX, Red River County, TX, Titus County, TX

The radar

The Little Rock radar (KLZK), 94 km from the middle of the area, began a volume at 04:42 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Shreveport, LA (KSHV), launched 00:00Z, 4.7 hours before the alert went out and 211 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Shreveport, LA at 00:00Z on 2011-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3108 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Shreveport, LA at 00:00Z on 2011-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
3108 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
891 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
199 m²/s²
Significant tornado parameter
2.3
Supercell composite
13.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 30, 7:49 PM CDTMesoscale DiscussionSPCClay, Greene, Izard, Lawrence, Randolph, Sharp and 1 more56 min
Apr 30, 8:47 PM CDTMesoscale DiscussionSPCArkansas, Clark, Conway, Faulkner, Garland, Grant and 12 more58 min
Apr 30, 9:26 PM CDTMesoscale DiscussionSPCHempstead, Howard, Little River, Miller, Sevier64 min
May 1, 1:16 AM CDTMesoscale DiscussionSPCArkansas, Clark, Cleburne, Conway, Craighead, Crittenden and 37 more59 min
May 1, 3:50 AM CDTMesoscale DiscussionSPCLee, Monroe, Phillips2 hr
May 1, 8:30 AM CDTMesoscale DiscussionSPCClark, Dallas, Garland, Hempstead, Hot Spring, Howard and 9 more30 min
May 1, 8:45 AM CDTSevere Thunderstorm WatchSPCClark, Columbia, Dallas, Garland, Hempstead, Hot Spring and 10 more6 hr
May 1, 12:12 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 34 more93 min
May 1, 12:47 PM CDTTornado WatchSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 27 more8 hr
May 1, 3:18 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 37 more87 min
May 1, 5:42 PM CDTMesoscale DiscussionSPCClark, Dallas, Garland, Grant, Hempstead, Hot Spring and 14 more3 hr
May 1, 5:43 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Clark, Cleveland and 37 more92 min
May 1, 1:40 AM CDTSevere Thunderstorm WatchSPCBryan, Love, Marshall7 hr
May 1, 3:19 AM CDTMesoscale DiscussionSPCCaddo, Carter, Comanche, Cotton, Garvin, Grady and 10 more86 min
May 1, 4:45 AM CDTTornado WatchSPCMcCurtain4 hr
May 1, 7:29 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Comanche and 11 more91 min
May 1, 1:14 AM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coleman, Collin, Comanche and 28 more2 hr

Nearby

Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Texas, 2011Mesoscale Discussions in Oklahoma, 2011Every mesoscale discussion in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.